1970 Ford Mustang - Up To Code

Let's start from at the beginning by saying that the car in these pictures is, in fact, a '70 Mustang. In place of the '70s two-headlight front end, owner Bob Cook installed the fenders and grille of a '69. The mixing and matching doesn't stop there. Between those swapped fenders, you'll find a swapped engine from an '03 Mustang, and not just any old 4.6 Modular engine, but the Top Dog, supercharged DOHC engine from the Mustang Cobra. But wait, there's more. Bob didn't stop the modernity at the firewall, he swapped the entire drivetrain from the Cobra: the T-56 six-speed, aluminum driveshaft, and independent rear suspension, too. Even the interior is a collaboration of '70 and '03 parts.

In case you're not familiar, Ford introduced the 4.6L engine in 1994, as a replacement for the 5.0L, Windsor-based engines. The modular engines were based on overhead cam architecture and were available in single-overhead-cam or dual-overhead-cam versions in either 4.6L or 5.4L displacements, in a variety of cars and trucks throughout their run. In the SN95 Mustangs ('94–'04) the GT got the SOHC 4.6, while the Cobras got the DOHC version. The '03 and '04 Cobras were noteworthy, however, because they came straight from the factory with an Eaton M112 Roots-type supercharger, which brought a jump in horsepower from 305 hp NA to 390 hp, with lots more power available with simple pulley changes. Those engines are tough, too, with forged pistons and rods, in addition to the forged cranks that all Cobra engines had. These features make the so-called Terminator engines very desirable for swaps such as this.

But what prompted Bob to undertake this swap is perhaps the most interesting part of the story. “The drum brakes sucked,” he said, “and my wife couldn't see over the dashboard. She asked me to raise the seat and fix the brakes.” Obviously, he got a little carried away in the process. Bob decided he wanted a fuel-injected engine, and that got him shopping insurance sales for donor parts. He ended up buying both an '03 and an '04 donor car, taking the useful parts, and selling the rest. Parting out those donor cars proved more lucrative than he expected, so he started buying SN-95 Mustangs for the sole purpose of parting them out on his eBay store, BL Auto Parts. That business took off, and four years ago, he left his long-running job as a GM dealership technician to run his online business full time. It's amazing how a simple seat-track adjustment can completely turn your life around.

During all this, Bob continued working on the '70, transforming it to the car you see here. Unlike LS engine swaps in GM cars, Modular swaps in unibody Fords aren't as simple as adding motor-mount adaptors to the new engine and dropping it in place. Bob ended up making a custom front subframe and swapping the entire floor from the new car into the old one. He also rebuilt the engine, swapping the Terminator rotating assembly into an earlier, aluminum engine block. He also upgraded to a more efficient 2.6L Kenne Bell twin-screw supercharger, and the result is a dyno-proven 688 hp—we can attest to how fast this car is. We rode with Bob on a high-speed blast around his rural Ohio home, and it was a total rush. It rides like a new Mustang, and the power delivery is brutal. All your senses say you're riding in a new car: the exhaust note is Mod-motor distinct, the whine of the supercharger screams Terminator Cobra, and the dash and seats reinforce your perception. But look out the windshield or rear window you see the cool, old Sportsroof. Bob may have created the ultimate Mustang, combining the iconic look of a '69–'70 Sportsroof but with modern, efficient, and fast running gear.

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Tech NotesWho: Bob Cook

What: '70 Ford Mustang

Where: Frazeysburg, OH

Engine: Bob did what we've always wanted to do with Ford's DOHC 4.6L engines: he combined the lightweight and strong Teksid block from '94–'98 Mark VIIIs and Cobras with the beefed-up rotating parts of the '03 Cobra. The cylinder heads for the '03–'04 Cobras, Mach 1s, and Mercury Marauder are among the best flowing heads available for a Mod motor, second only to the '00 Cobra R and Ford GT heads. Bob augmented their performance with a quartet of Comp XE274BH-116 cams and their requisite valvesprings. The Kenne Bell supercharger was a used parts score, and he added a Fluidyne air-to-water intercooler. Mann Performance of Newark, OH, did the machine work, and ARP fasteners and Fel-Pro gaskets seal it up. On the dyno, the engine made 688 hp and 605 lb-ft of torque on 14-psi boost.

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Transmission/rearend: A Cobra T56 six-speed backs up the engine. Bob added a Spec aluminum flywheel and McLeod clutch and an aluminum driveshaft leading back to the '03 Cobra's independent rear suspension, housing 3.55:1 gears and stock '03 Cobra axles.

Exhaust: Stainless Works headers for an '03 Cobra lead to a 3-inch exhaust system with a pair of Magna Flow mufflers.

Suspension: Bob and his son, Rob, built a custom front K-member out of chromoly tubing. It incorporates the attaching points for the stock '03 Cobra's front suspension, which includes Bilstein struts, Hypercoil 700 lb/in springs, an Eibach 13⁄8-inch sway bar and the Cobra's rack-and-pinion steering system. Bilstein shocks and 475 lb/in Hypercoil springs also reside out back, as does another Eibach sway bar.

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Brakes: Stock '03 Cobra brakes are found front and rear. Bob was even able to make the Cobra's ABS and traction control systems work with the transplant.

Swap modifications: Putting it in very general terms, Bob cut the floor out of his '70 Mustang in and welded in the floor of an '03 Cobra. That is oversimplifying things, however. There is a 7-inch difference in wheelbase between the two cars, the '70 is longer, so Bob had to cut the '03 floor in several sections to make it fit the Sportsroof. The Cobra's shock towers were extended 7 inches forward from their original position, requiring Bob to make a filler panel in between. He also used most of the Cobra's firewall, and was therefore able to keep that car's brake master cylinder and windshield wiper motor (attached to the '70's wiper arms). The '70 is also a bit wider than the '03, so Bob and his son filled the gaps between the rocker panels and floor with some rectangle tubing, which has the added benefit of strengthening the chassis. Using the '03 floor means the independent rear suspension and fuel system of the new car can work with the old one. Bob just needed to lengthen the fuel and brake lines to make up for the added length.

Paint and body: Even the '70 Sportsroof's body is a collection of several model year's styling elements. Bob added the fenders and grille of a '69 Mustang, and the rear valance and taillights from a '67. Brandon Collins did the paint job, using House of Kolor Tangelo Orange Pearl with an orange candy coat added before the clearcoat.

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Interior: Bob adapted the '03 Cobra's dash to fit the '70. The seats are from a '01 Bullitt and were reupholstered by Recovery Room in Thornville, OH.